1. Field of the Invention
The present invention relates to a rewinding device for cameras. More specially, the invention relates to a rewinding device adapted to a manual winding camera with a manual rewinding knob in which such a film cartridge is used that the leader portion or tip of the film is entirely rewound into the cartridge in the both cases of unused and used film.
2. Description of the Related Art
There has been suggested a specific combination of a film cartridge and a camera in Japanese Laid-Open Patent Application No. Hei.2-114248. In such a combination, the film cartridge has a film winding shaft and a casing having a film gate for keeping the film wound on the winding shaft lightproof. And the feature of the film cartridge is that the abovementioned winding shaft is set in a predetermined phase of rotation in the state of unused film.
According to the Laid-Open Patent Application, both of the winding shaft of the unused film cartridge and a fork of the camera before loading the film cartridge are set at a predetermined phase of rotation. Therefore, the film cartridge can be loaded to the camera promptly, with any misfunctioning or trouble effectively prevented.
In the abovementioned Laid-Open Patent Application, the leader portion of the film is entirely rewound into the casing in the state of unused film as well as used film for the convenience of handling the film cartridge. And when the leader portion is thrust outside the cartridge to a winding shaft on the camera side by means of a film thrusting mechanism in the camera and connected with the winding shaft, the film loading is completed. Accordingly, loading action is simplified because it is needless to pull out the leader portion nor adjust the length thereof.
As to the conventional film cartridge well-known to public heretofore, on the contrary, a part of the leader portion of the film is out of the casing in the state of unused film. To load the film, the leader portion has to be pulled for a certain length and connected to the winding shaft in the camera. When the film is finished, the film is entirely rewound into the casing. Therefore, distinction between used and unused cartridge is made by whether the leader portion of the film is out of the casing or not.
As mentioned above, however, as to the cartridge disclosed in the abovementioned Japanese Laid-Open Patent Application No. Hei.2-114248, the leader portion of the film is in the cartridge in the case of both unused and used cartridges. So, it is impossible to know whether the cartridge is unused or used by means of the leader portion of the film.
Accordingly, in the cartridge disclosed in the abovementioned Japanese Laid-Open Patent Application No. Hei.2-114248, the phase of rotation of the winding shaft of the cartridge is utilized to represent or inform the camera whether the cartridge is used or unused. That is, the phase of rotation of the abovementioned winding shaft of the cartridge in the unused state is different from that in the used state to make it possible to judge the state of the cartridge. Further, the used cartridge is prevented from being used again by means of setting the fork at a predetermined phase of rotation connectable only with the winding shaft of the unused cartridge at the predetermined phase of rotation.
The phase of rotation of the winding shaft of the cartridge is represented as in the illustration of the cartridge 10 in FIG. 5, for instance. The winding shaft 20 is located in the cartridge 10. The winding shaft 20 is composed to rotate in connection with the fork (not shown) of the driving portion in the camera body. When the winding shaft 20 is rotated in the direction of arrow m1, the film is thrust out of the film gate 12 (in the direction of arrow m3). On the other hand, when the winding shaft 20 is rotated in the direction of arrow m2, the film that has been out is rewound into the case 11 (in the direction of arrow m4).
In a motor winding camera, the winding shaft can be controlled by the camera to stop at a predetermined phase of rotation after the rewinding is finished.
In manual winding camera, however, the film is wound by manually rotating the rewinding knob. Accordingly, the operator has to adjust the winding shaft at the abovementioned predetermined phase of rotation when terminating the operation of the rewinding knob. This makes the operation difficult.